如何从导航栏中打开一个新片段？

如今,导航抽屉是一种全新的趋势设计.我们使用两种布局:主要内容布局和抽屉列表布局,同时为导航抽屉活动设计xml.layout(布局).我在这里回答你所有愚蠢的问题.

单击导航抽屉时,如何让我的应用在主视图中打开一个新片段？

只需在抽屉列表项上添加clicklistener,并根据单击列表项的位置替换主要内容中的片段.

示例代码:

    // The click listener for ListView in the navigation drawer
    @SuppressWarnings("unused")
    private class DrawerItemClickListener implements ListView.OnItemClickListener {
        @Override
        public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
            selectItem(position);
        }
    }

    private void selectItem(int position) {

        Fragment newFragment;
        FragmentTransaction transaction = getFragmentManager().beginTransaction();

        switch (position) {
        case 0:
            newFragment = new f1();
            transaction.replace(R.id.content_frame, newFragment);
            transaction.addToBackStack(null);
            transaction.commit();
            break;

        case 1:
            newFragment = new f2();
            transaction.replace(R.id.content_frame, newFragment);
            transaction.addToBackStack(null);
            transaction.commit();
            break;

        case 2:
            newFragment = new f3();
            transaction.replace(R.id.content_frame, newFragment);
            transaction.addToBackStack(null);
            transaction.commit();
            break;

        case 3:
            newFragment = new f4();
            transaction.replace(R.id.content_frame, newFragment);
            transaction.addToBackStack(null);
            transaction.commit();
            break;  


        }
        //DrawerList.setItemChecked(position, true);
        setTitle(ListTitles[position]);
        DrawerLayout.closeDrawer(DrawerList);   
    }

这里是f1,f2.f3和f4是不同的片段,每个片段都有自己的布局.你必须通过继承fragment类为它们创建单独的java类.

单击导航抽屉时,是否可以使用标签打开多个可滑动的片段？

为了在片段中实现选项卡,您可以在该特定片段中使用tabhost.假设您要在片段f_main中添加制表符.

F_main.xml的布局

<TabHost 
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@android:id/tabhost"
    android:layout_
    android:layout_ >

   <LinearLayout
        android:layout_
        android:layout_
        android:orientation="vertical" >

        <TabWidget
            android:id="@android:id/tabs"
            android:layout_
            android:layout_
            android:layout_weight="0"
            android:orientation="horizontal" />

        <FrameLayout
            android:id="@+id/tabFrameLayout"
            android:layout_
            android:layout_
            android:layout_weight="1" />
    </LinearLayout>

</TabHost>

然后使用相应的布局和java类创建其他片段f_tab1和f_tab2.两个标签片段的布局可以相同或不同.在这里,我采用相同或共同的布局.

<?xml version="1.0" encoding="utf-8"?>
    <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
        android:layout_
        android:layout_
        android:orientation="vertical" >

        <TextView android:id="@+id/google_map"
            android:layout_
            android:layout_
            android:text="MAP"/>

    </LinearLayout>

F_tab1.java片段的代码

import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;

public class F_tab1 extends Fragment {

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
            Bundle savedInstanceState) {

        View view=inflater.inflate(R.layout.friends_list, container,false);


        return view;
    }

}

另一个片段的代码.即F_tab2.java

import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;

public class F_tab2 extends Fragment {

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
            Bundle savedInstanceState) {

        View view=inflater.inflate(R.layout.friends_list, container,false);


        return view;
    }

}

现在,只需在前面提到的抽屉列表中使用clicklistener,即可在抽屉列表中的项目单击上加载F_main,这将进一步加载主内容视图中F_main fragmnet中的选项卡.

如何使"标题"可扩展/可折叠？

好吧,我不知道NV抽屉是否提供此功能.但它提供了一个功能,可根据所选的抽屉项目或加载的主要内容片段切换操作栏标题.

如导航抽屉设计指南中所述,您应该在抽屉可见时修改操作栏的内容,例如更改标题并删除与主要内容相关的操作项.下面的代码显示了如何通过使用ActionBarDrawerToggle类的实例覆盖DrawerLayout.DrawerListener回调方法来实现此目的,如下所示

 public class MainActivity extends Activity {
    private DrawerLayout mDrawerLayout;
    private ActionBarDrawerToggle mDrawerToggle;
    private CharSequence mDrawerTitle;
    private CharSequence mTitle;
    ...

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        ...

        mTitle = mDrawerTitle = getTitle();
        mDrawerLayout = (DrawerLayout) findViewById(R.id.drawer_layout);
        mDrawerToggle = new ActionBarDrawerToggle(this, mDrawerLayout,
                R.drawable.ic_drawer, R.string.drawer_open, R.string.drawer_close) {

            /** Called when a drawer has settled in a completely closed state. */
            public void onDrawerClosed(View view) {
                getActionBar().setTitle(mTitle);
                invalidateOptionsMenu(); // creates call to onPrepareOptionsMenu()
            }

            /** Called when a drawer has settled in a completely open state. */
            public void onDrawerOpened(View drawerView) {
                getActionBar().setTitle(mDrawerTitle);
                invalidateOptionsMenu(); // creates call to onPrepareOptionsMenu()
            }
        };

        // Set the drawer toggle as the DrawerListener
        mDrawerLayout.setDrawerListener(mDrawerToggle);
    }

    /* Called whenever we call invalidateOptionsMenu() */
    @Override
    public boolean onPrepareOptionsMenu(Menu menu) {
        // If the nav drawer is open, hide action items related to the content view
        boolean drawerOpen = mDrawerLayout.isDrawerOpen(mDrawerList);
        menu.findItem(R.id.action_websearch).setVisible(!drawerOpen);
        return super.onPrepareOptionsMenu(menu);
    }
    }